DESCRIPTION (Applicant's abstract): The proposed research is designed to explore the effects of attributions of fun, importance, and combinations thereof as reasons for engagement activities. Established social-psychological paradigms are employed to test the hypothesis that actors have mental models of motivations for engaging in activities, and drawing on Mandler's (1975) model of the disruptive motivational effects of 'disconfirmed expectancies', performance will be better when the instructional framing for engaging in a particular activity matches versus mismatches the mental model of the actor for that activity. The proposed experiments are designed to test this hypothesis for activities pre-determined to be: "just fun"; "just important"; "primarily fun but also important"; "primary important but also fun"; and "equally fun and important". Consensual mental models for a set of activities will first be examined, controlling for the actual nature of the task. Then individual differences in mental models for the same activity will be investigated. This research program could help to improve individuals' performance on different activities and increase their desire to perform the activities in the future. The mental health implications are manifold, suggesting interventions that would improve individuals performance and subjective well-being. Theoretically, the proposed research is designed to extend our understanding of how motivational attributions can combine in a number of ways to influence performance depending on contextual framing.